Motor size for a 25 tonne press?

[Ross Moffett]

Hi Y'all,

 

So I've been doing loads of research and designing and I've finally come to the stage where I can start ordering the parts for the press. Anyways here's my reason for posting, my calculations and the page about the pump say for a 10.51 GPM, 3000 psi, 2 stage pump I need a 7 hp motor. BUT Coal Iron Works 25 ton press uses only a 5 hp motor for a 13 GPM pump and McNabb's 24-ton press uses a 3 hp (not sure what pump though)!?! Am I doing my calculations wrong or something? I'm going to be using a 5 X 8-inch tie rod cylinder.

Thanks in advance!

Here's a quick "animation" of the press.

The press is just over 7.5 feet and working height is around 3.5 feet.

 

"Edit" added some images in case the "animation" doesn't work.

 

 

 

Recording #4.mp4

[BeaverNZ]

I think the best answer is talk to a hydraulic service specailist shop that way you will be talking to a profesional who knows what they are talking about. The other units you talked about may have been setup so the motor is overloaded just for a short term which most motors will cope with for short periods so long as they are lightly loaded after to disapate the heat from the windings, most small air compressors are like that or the said presses may have different sized second stages in the pump if they have two stage pumps to pump less oil so take less power but will be slower. Speed and tonnage reqiures HP  Cheers Beaver

[Ross Moffett]

BeaverNZ - Good advice will do.

[Jspool]

My press uses a 5”x8” throw 2” ram cylinder. Its powered by a 5hp 5gpm pump at 2500psi and gives me 1”per second extension.

Being a single stage pump it basically maintains its speed after contact.